comonad-transformers-0.1.1: Haskell 98 comonad transformers

Portabilityportable
Stabilityprovisional
MaintainerEdward Kmett <ekmett@gmail.com>

Control.Comonad.Trans.Env

Description

The environment comonad transformer (aka coreader). This adds an extra value that can be accessed in the environment.

Left adjoint to the reader comonad.

Documentation

type Env e = EnvT e IdentitySource

env :: e -> a -> Env e aSource

runEnv :: Env e a -> (e, a)Source

data EnvT e w a Source

Constructors

EnvT e (w a) 

Instances

ComonadTrans (EnvT e) 
Functor w => Functor (EnvT e w) 
Comonad w => Comonad (EnvT e w) 

runEnvT :: EnvT e w a -> (e, w a)Source

ask :: EnvT e w a -> eSource